Chemical Basis of Life Jan 30 11:42 AM In order to understand digestion and nutrition, we need some basic biochemistry Chemistry studies the composition of matter and its changes as well as the change in energy that results Body functions result from chemical changes with in the body. Jan 30 11:45 AM 1
All matter is made of of atoms Elements are made up of one type of atom 90 naturally occurring elements when two or more atoms bond, a molecule is formed when the atoms are from two or more different elements, we have a compound. Jan 30 11:47 AM Atomic structure: The center region is called the nucleus the nucleus is made up of neutrons and protons They are held together by nuclear forces Outside of the nucleus are electrons Jan 30 11:52 AM 2
Protons are positively charged There are the same number of protons in every atom of a given element Neutrons are neutral in charge The number of neutrons changes Atoms of the same element with different numbers of neutrons are called isotopes The atomic mass of an atom is equal to the # of protons plus the number of neutrons Jan 30 11:54 AM Electrons are negatively charged in a neutral atom, the number of electrons and protons are the same. If an atom loses or gains an electron, it then has a charge An atom with a charge is an ion Jan 30 11:57 AM 3
Bonding When two or more atoms are chemically bonded, they form molecule Which atoms will bond with which is determined by the electrons We will look at the two most basic categories of bonding: covalent ionic Jan 30 11:59 AM Covalent bonds Involve the sharing of pairs of electrons Atoms may share 1, 2 or 3 pairs of electrons They do this in order to become more stable; This is achieved by sharing enough electrons to have eight in the outer energy level of an atom. (also known as the rule of octets.) Jan 30 12:01 PM 4
Sep 20 12:40 PM Sep 20 12:46 PM 5
Sep 20 12:39 PM Ionic bonds The bonding of atoms due to the formation of ions. One atom gains an electron, another loses one or more. The opposite charge holds them together Jan 30 12:07 PM 6
Chemical reactions: The formation or breaking of bonds in a compound or compounds in order to form new compounds Chemical reactions are accompanied by a change in energy The bonds of a chemical hold energy When they are broken, energy is released. Jan 30 12:22 PM Jan 30 1:59 PM 7
When dissolved in water, some chemicals will release ions Since ions are charged particles, ionic solutions will conduct an electric current Therefore, ionic solutions are called electrolytes Electrolytes that release H + are referred to as acids electrolytes that release ions that will combine with H + are bases Jan 30 12:24 PM We use the ph scale to measure the H + concentration this scale goes from 0 to 14 7 is neutral less than 7 is acidic greater than 7 is basic or alkaline Jan 30 12:28 PM 8
Sep 20 12:58 PM The ph scale is logarithmic Each whole ph value below 7 is ten times more acidic than the next higher value. For example, ph 4 is ten times more acidic than ph 5 and 100 times (10 times 10) more acidic than ph 6. Jan 30 12:31 PM 9
The same holds true for ph values above 7, each of which is ten times more alkaline (another way to say basic) than the next lower whole value. For example, ph 10 is ten times more alkaline than ph 9 and 100 times (10 times 10) more alkaline than ph 8. Jan 30 12:33 PM What makes up cells? There are both inorganic and organic compounds in the cells of living organisms Inorganic: compounds that do not contain Carbon Organic: Compounds that contain carbon Jan 30 12:35 PM 10
Inorganic substances : Water Oxygen Carbon dioxide** Salts **although CO 2 contains carbon, it is considered to be inorganic. It is a waste product of metabolic functions. Jan 30 1:00 PM Water is the most abundant compound in living matter. In and adult: 60 67% of total weight is water Necessary as a solvent dissolves other materials necessary for metabolism. Necessary for transport of materials from one part of the organism to another. Absorbs and transports heat Jan 30 1:04 PM 11
Oxygen We take in oxygen in the form of O 2 gas enters through the respiratory system carried by blood Carbon dioxide Waste product of metabolic processes Jan 30 1:05 PM Salts found in tissues and fluid throughout the body Provide the ions necessary for *muscle contraction *transport of substances into and out of cells Feb 1 10:54 AM 12
Organic substances Feb 1 10:56 AM Carbohydrates made up of carbon, hydrogen, oxygen the ratio of hydrogen to oxygen is generally 2:1 generally chains of carbon of varying lengths Feb 1 10:56 AM 13
Monomers: simple sugars or monosaccharides There are 3 found in the human organism: glucose fructose galactose Feb 1 10:59 AM Two monosaccharides bond to form a disaccharide The process by which they bond is called condensation polymerization glucose + glucose: maltose most rare disaccharide glucose + fructose: sucrose table sugar glucose + galactose : lactose milk sugar Feb 1 11:07 AM 14
Sep 23 12:50 PM Function of carbohydrates provide energy part of the cell structure Feb 1 11:15 AM 15
Lipids include: fats oils phospholipids steroids Feb 1 11:16 AM Fats: store energy composed of Carbon Hydrogen Oxygen (much smaller proportion of oxygen than carbs) Feb 1 11:18 AM 16
Feb 1 11:34 AM Feb 1 11:35 AM 17
Feb 1 11:36 AM Feb 1 11:38 AM 18
Sep 23 1:05 PM Sep 23 1:05 PM 19
Sep 23 1:01 PM Phospholipids: Similar to triglycerides glycerol fatty acids only 2 phosphate group replaces the 3rd The phosphate portion makes it soluble in water! (hydrophilic: where are these located?) Feb 1 2:11 PM 20
Feb 1 2:11 PM Steroids 4 connected rings of Carbon atoms testosterone Feb 7 12:30 PM 21
Proteins C, H, O, N Made up of amino acids act as energy sources act as enzymes act as cell receptors (think "B cell video") Feb 7 12:35 PM One end has an amino group : NH 2 The other end has a carboxyl group: COOH C \ O OH Feb 7 12:38 PM 22
DENATURING OF PROTEINS: The hydrogen bonds in a protein determine the strcture When these bonds are broken, the protein cannot do it's job because the sturcture breaks down: This is called denaturing Feb 7 12:40 PM Nucleic acids the two we have in the body are: DNA & RNA : Deoxyribonucleic acid Ribonucleic acid Feb 7 12:41 PM 23
The nucleic acid is made up of nucleotides These consist of: phosphate (PO 3 ) sugar nitrogen base Guanine Adenine Thymine Cytosine Uracil Feb 7 12:42 PM Function of DNA: Stores genetic information Function of RNA makes protein Feb 7 12:43 PM 24